Thermal module

ABSTRACT

A thermal module includes a heat radiating unit, a heat transfer unit, and at least one cross-flow fan. The heat radiating unit has an air inlet and an air outlet that communicate with each other. The heat transfer unit has a heat absorbing section attached to a heat source and a heat dissipating section extended from the heat absorbing section to connect to the heat radiating unit. The cross-flow fan is arranged opposite to the heat radiating unit with an air-out side of the cross-flow fan located adjoining to the air inlet of the heat radiating unit. With the above arrangements, the thermal module occupies a largely reduced area while providing largely upgraded heat dissipation effect.

FIELD OF THE INVENTION

The present invention relates to a thermal module, and more particularly to a thermal module that utilizes a cross-flow fan to reduce the area occupied by the thermal module while upgrading the heat dissipation ability thereof and overcoming the problem of vibration and noise caused by long blades of the conventionally designed fan used with a thermal module.

BACKGROUND OF THE INVENTION

Due to the rapid development in the electronic industry, the density of transistors contained in various kinds of chips, such as processors, executing units and the like, also increases quickly. While the electronic elements can process data more quickly, they also consume more power and generate more heat during the operation thereof. For the central processing unit (CPU) to work stably, it is necessary to use a high-efficiency heat radiating unit to radiate the high amount of heat produced by the CPU in operation. To maintain highly efficient heat radiating function, there is no way but to gradually increase the volume and weight of the heat radiating unit. However, the large-sized heat radiating unit forms a bottleneck in the design of notebook computers, tablet computers, smart mobile phones, and smart handheld electronic devices that all have very limited internal space.

FIG. 1 is a perspective view of a conventional thermal module 1, which includes a centrifugal fan 10, a heat pipe 11, and a heat radiating unit 12. The centrifugal fan 10 produces flowing air in order to carry away the heat transferred to the heat radiating unit 12 and achieve the purpose of lowering the temperature of the heat-generating electronic element. The performance of the conventional thermal module 1 is determined by the air flow and the air pressure produced by the centrifugal fan 10 as well as the area provided by the radiating unit 12 for heat exchange. To provide increased area for heat exchange, the radiating unit 12 is usually designed to have radiating fins with extended length. While the length-extended radiating fins enable the radiating unit 12 to provide improved heat radiating effect, they also have excessively large volume and are absolutely not suitable for use with the notebook computer that is characterized by light weight as well as slim and compact configuration.

To meet the requirements for light weight as well as slim and compact configuration, all the elements in the electronic devices, including the centrifugal fan 10, have been miniaturized as much as possible. However, the miniaturized centrifugal fan 10 can only produce relatively reduced air flow, which results in limited heat dissipation effect. Meanwhile, the miniaturized centrifugal fan 10 has blades that have relatively large areas but reduced thickness and therefore tend to deflect and swing and accordingly produce vibration and noise when the centrifugal fan 10 operates.

Therefore, it has become an important target of related manufacturers to work out a way for effectively upgrading the performance of the radiating unit 12 without increasing the volume thereof.

In brief, the conventional thermal module has the following disadvantages: (1) having a relatively large volume; (2) providing poor heat dissipating effect; and (3) tending to produce vibration and noise during operation.

It is therefore tried by the inventor to develop an improved thermal module to overcome the problems in the conventional thermal modules.

SUMMARY OF THE INVENTION

A primary object of the present invention is to provide a thermal module that utilizes a cross-flow fan to reduce the occupied area thereof.

Another object of the present invention is to provide a thermal module that provides upgraded heat dissipation ability and reduces or improves the vibration and noise caused by deflection of excessively long fan blades.

To achieve the above and other objects, the thermal module according to the present invention includes a heat radiating unit, a heat transfer unit, and at least one cross-flow fan. The heat radiating unit has an air inlet and an air outlet communicating with the air inlet. The heat transfer unit has a heat absorbing section and a heat dissipating section. The heat absorbing section is attached to a heat source, and the heat dissipating section is connected to the heat radiating unit. The cross-flow fan is arranged opposite to the heat radiating unit with an air-out side of the cross-flow fan located adjoining to the air inlet of the heat radiating unit.

By including the cross-flow fan in the thermal module, the thermal module can have effectively reduced occupied area thereof to be advantageously used in a limited space, and the large volume of air flow produced by the cross-flow fan is able to effectively upgrade the heat dissipation effect of the thermal module. In addition, by using the cross-flow fan, the problem of vibration and noise caused by the deflection and swing of excessively long blades of other types of fans as found in the conventional thermal module can be effectively overcome.

BRIEF DESCRIPTION OF THE DRAWINGS

The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein

FIG. 1 is an assembled perspective view of a conventional thermal module;

FIG. 2 is an exploded perspective view of a thermal module according to a preferred embodiment of the present invention;

FIG. 3A is another exploded perspective view of the thermal module according to the preferred embodiment of the present invention; and

FIG. 3B is an assembled view of FIG. 3A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described with some preferred embodiments thereof and with reference to the accompanying drawings.

Please refer to FIGS. 2 and 3A that are two exploded perspective views of a thermal module 2 according to a preferred embodiment of the present invention, and to FIG. 3B that is an assembled view of FIG. 3A. As shown, the thermal module 2 includes a heat radiating unit 21, a heat transfer unit 22, and at least one cross-flow fan 23. In the illustrated preferred embodiment, the heat radiating unit 21 is shown as a radiating fin assembly. However, it is understood the heat radiating unit 21 is not necessarily limited to the radiating fin assembly, but can be a heat sink or any other element capable of radiating heat.

The heat radiating unit 21 includes a plurality of radiating fins 211, and defines an air inlet 213 and an air outlet 214, which are communicating with each other. Any two adjacent radiating fins 211 together define a flow guiding passage 212 between them. The flow guiding passages 212 communicate with the air inlet 213 and the air outlet 214 for guiding air at the air inlet 213 to flow toward the air outlet 214. When the air flows through the flow guiding passages 212, heat transferred to the radiating fins 211 is carried away by the air to the air outlet 214 and dissipates into external environment therefrom. Therefore, good heat dissipation effect can be efficiently achieved.

The heat transfer unit 22 can be a heat pipe, a heat spreader, a vapor chamber, or any other element capable of transferring heat. While the heat transfer unit 22 in the illustrated preferred embodiment is shown as a heat pipe, it is not necessarily limited thereto. The heat transfer unit 22 includes a heat absorbing section 221 and a heat dissipating section 222. The heat absorbing section 221 can be directly attached to a heat source 24, as shown in FIG. 2, or be attached to one side of a seat 20, as shown in FIGS. 3A and 3B. The seat 20 has another opposite side in contact with the heat source 24, which can be, for example, a central processing unit, a south bridge chip, a north bridge chip, a graphics chip or an executing unit, for absorbing heat generated by the heat source 24. The heat absorbing section 221 of the heat transfer unit 22 attached to the seat 20 further absorbs and transfers the heat from the seat 20 to the heat dissipating section 222, from where the heat is further transferred to the radiating fins 211 that are in contact with the heat dissipating section 222. Finally, the heat is radiated from the radiating fins 211 into external environment and dissipates into ambient air.

As can be seen from FIGS. 3A and 3B, the heat dissipating section 222 is outwardly extended from the heat absorbing section 221 to connect to the radiating fins 211 of the heat radiating unit 21. The cross-flow fan 23 is arranged opposite to the heat radiating unit 21 and has one side located adjoining to the air inlet 213.

The cross-flow fan 23 includes a housing 231, a blade assembly 232, and a motor 233. The housing 231 has an air-in side 2311 and an air-out side 2312 communicating with each other. The air-out side 2312 of the cross-flow fan 23 is faced toward and connected to the air inlet 213 of the heat radiating unit 21. And, a receiving space 2313 is defined between the air-out side 2312 and the air-in side 2311 for receiving the blade assembly 232 therein.

The motor 233 is arranged to an end of the housing 231 to connect to the blade assembly 232 for driving the latter to rotate. The blade assembly 232 includes a plurality of blades 2321 and a plurality of annular rims 2322. The blades 2321 are located between any two adjacent annular rims 2322 and are arranged transverse to and along a circumference of the annular rims 2322.

In practical implementation, the blades 2321 and a shaft (not shown) of the blade assembly 232 can be adjusted in length and in a connection structure therebetween according to required air volume and available space for the thermal module 2. Further, since the cross-flow fan 23 is characterized by high and uniform air flows as well as low noise production, it is able to provide effectively upgraded air volume and overcome the problem of vibration and noise caused by the deflection and swing of excessively long blades of fan as found in the conventional thermal module.

Please refer to FIG. 2. When the motor 233 of the cross-flow fan 23 drives the blade assembly 232 to rotate, ambient air is guided through the air-in side 2311 into the receiving space 2313 before being blown out via the air-out side 2312 into the air inlet 213 of the heat radiating unit 22 located opposite to the cross-flow fan 23. The air blown into the air inlet 213 flows through the flow guiding passages 212 toward the air outlet 214 while carries heat away from the radiating fins 211, so as to achieve the effect of quickly dissipating heat into external environment.

By combining the cross-flow fan 23 with the heat radiating unit 21 and the heat transfer unit 22, the thermal module 2 of the present invention not only effectively reduces the occupied area thereof for advantageously using in a limited space, but also produces good heat dissipation effect without the need of increasing the number of fans or heat radiating units because the cross-flow fan 23 is able to effectively increase the volume of air flow to largely upgrade the heat dissipation effect of the thermal module 2. In addition, by using the cross-flow fan 23, the problem of vibration and noise caused by the deflected and swinging long blades of fan as found in the conventional thermal module can be effectively overcome.

In brief, the thermal module according to the present invention is superior to the conventional ones due to the following advantages: (1) being miniaturized to have a slim configuration; (2) providing upgraded heat dissipation effect; and (3) overcoming the problem of vibration and noise caused by thinned blades of the conventional centrifugal fan.

The present invention has been described with a preferred embodiment thereof and it is understood the preferred embodiment is illustrated only to facilitate easy explanation of the present invention and not intended to restrict the present invention in any way, and many changes and modifications in the described embodiment can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims. 

What is claimed is:
 1. A thermal module, comprising: a heat radiating unit having an air inlet and an air outlet communicating with the air inlet; a heat transfer unit having a heat absorbing section and a heat dissipating section; the heat absorbing section being attached to a heat source, and the heat dissipating section being faced toward and connected to the heat radiating unit; and at least one cross-flow fan being arranged opposite to the heat radiating unit with one side of the cross-flow fan located adjoining to the air inlet of the heat radiating unit.
 2. The thermal module as claimed in claim 1, wherein the heat absorbing section of the heat transfer unit is attached to one side of a seat, and the seat has another opposite side in contact with the heat source, such that heat generated by the heat source is transferred to the heat radiating unit via the seat and the heat transfer unit.
 3. The thermal module as claimed in claim 1, wherein the heat radiating unit is selected from the group consisting of a radiating fin assembly, a heat sink, and any other element capable of radiating heat therefrom.
 4. The thermal module as claimed in claim 1, wherein the heat transfer unit is selected from the group consisting of a heat pipe, a heat spreader, a vapor chamber, and any other element capable of transferring heat.
 5. The thermal module as claimed in claim 1, wherein the heat radiating unit includes a plurality of radiating fins, and a flow guiding passage is defined between any two adjacent ones of the radiating fins; and the flow guiding passages communicating with the air inlet and the air outlet.
 6. The thermal module as claimed in claim 1, wherein the cross-flow fan includes a housing, a blade assembly, and a motor; the housing having an air-in side and an air-out side communicating with the air-in side; the air-out side being located adjoining to the air inlet of the heat radiating unit; the air-out side and the air-in side together defining a receiving space therebetween for receiving the blade assembly therein; and the motor being arranged to an end of the housing to connect to the blade assembly for driving the latter to rotate.
 7. The thermal module as claimed in claim 6, wherein the blade assembly includes a plurality of blades and a plurality of annular rims; the blades being provided between any two adjacent ones of the annular rims, and being arranged transverse to and along a circumference of the annular rims. 